1. Technical Field
The present invention relates to a liquid ejecting apparatus such as an ink jet recording apparatus, and a control method thereof, and in particular, to a liquid ejecting apparatus in which cleaning of a nozzle is performed by causing liquid to be forcibly ejected from the nozzle of a liquid ejecting head, and a control method thereof.
2. Related Art
Liquid ejecting apparatuses include a liquid ejecting head which can eject liquid as droplets from a nozzle, and eject various liquids from the liquid ejecting head. As a representative liquid ejecting head, for example, there is an image recording apparatus such as an ink jet recording apparatus which includes an ink jet recording head (hereinafter, referred to as recording head), and performs recording by ejecting ink of a liquid form from a nozzle of the recording head as ink droplets (hereinafter, referred to as printer), or the like.
In the above described printer, a cleaning operation is performed on a regular basis, in order to recover or maintain an ejecting property of ink which is ejected from a nozzle of a recording head. For example, a suction operation of forcibly discharging ink from a nozzle by reducing a pressure in a sealing space using a pump is performed in a state in which the nozzle is sealed in the sealing space of a cap, by causing the cap to come into contact with a nozzle face on which the nozzle of the recording head is formed (for example refer to JP-A-2003-276214). Due to the suction operation, it is possible to discharge thickened ink, bubbles, or the like, along with ink to a discharging path on which a pump is provided. In addition, in a sealing space of a general cap in the related art, an absorber such as sponge which absorbs ink is provided. The absorber absorbs part of ink which is discharged in a suction operation. For this reason, splattering or bubbling of ink which is discharged into the cap in the suction operation is suppressed by the absorber.
Meanwhile, the above described recording head is also applied to a printer for textile printing which performs recording of an image with respect to cloth such as a textile, a knitted material, a non-woven fabric, or the like, by making use of characteristics which can cause a liquid of a minimum quantity to land on a predetermined position accurately. In addition, as the ink for textile printing, for example, ink which contains a resin is used. By a resin being contained in ink, it is possible to cause a coloring material such as pigment to be fixed on cloth.
The above described ink which includes a resin is easy to solidify, since contained moisture, solvent, or the like, evaporates. For this reason, ink which is absorbed into an absorber of a cap is solidified and accumulated due to a suction operation. As a result, there also is a concern that a discharging path may become clogged, and the suction operation may not be normally performed, not only that an absorption function of ink using the absorber may be lost. In addition, there also is a concern that a nozzle face may be damaged by ink which is solidified and accumulated when the cap comes into contact with the nozzle face.
A configuration in which the absorber is not provided in the sealing space of the cap has been proposed. However, in such a configuration, inconveniences, for example, bubbles being mixed into ink in the nozzle in the suction operation, or a meniscus of the nozzle being broken down become more prevalent. The reason why is that, in the suction operation, in a configuration in which the absorber is not provided in the sealing space, a flow velocity of sucked ink becomes fast compared to the configuration in which the absorber is provided. That is, when the flow velocity of the ink which is sucked from the nozzle becomes fast, a behavior (vibration, or the like) of the meniscus of the nozzle becomes intense, and air is easily mixed into ink in the nozzle. In addition, there also may be a case in which air is mixed into ink due to bubbles of ink which easily occur in the cap, and adhering of the bubbles to the meniscus of the nozzle, or the like, when the inside of the cap is open to the atmosphere due to opening of an atmosphere opening valve after the suction operation, or the like. As a result thereof, there has been a concern that dot omission in which ink is not ejected from the nozzle may occur.